EDTA

Ethylenediaminetetraacetic acid (EDTA)

EDTA is used to chelate cations, specifically Mg²⁺. We use it mainly as one of the two ingredients in TE buffer

Molar mass = 292.24 g·mol^-1

0.5 M EDTA, pH 8: For 500 mL

• Resuspend 93.05 g Na₂•EDTA•₂ (disodium dyhydrate) in about 400 mL of ddH₂O
• Add about 9 g solid NaOH
• Once all the NaOH dissolves, slowly adjust the pH with 10 N NaOH
• Bring up the volume to 500 mL with ddH₂O

Note: EDTA will not completely dissolve until the pH reaches 8